[Curly Woods]

OK I have a question about a redo of my listening room.  20 feet wide 30 feet long.  Isolation is not an issue as my room is about the garage.  What benefit would double sheet rock provide me in this situation?  Green Glue? The channel system mentioned earlier? 
  I was thinking of framing out the corners like a triangle(3' from either wall) to remove resonant corners.  Would this be a worthwhile option?

[Big Red Machine]

OK I have a question about a redo of my listening room.  20 feet wide 30 feet long.  Isolation is not an issue as my room is about the garage.  What benefit would double sheet rock provide me in this situation?  Green Glue? The channel system mentioned earlier? 
  I was thinking of framing out the corners like a triangle(3' from either wall) to remove resonant corners.  Would this be a worthwhile option?

No.  Fill them with triangles of 703 floor to ceiling 24 inches at the face to the room.  8 pieces per sheet.  If you frame them and drywall them they you haven't trapped any bass and you're back to square one.  If you don't need to keep sound from bugging others outside the room then you don't need to redo your room unless of course you are on a busy street and the noise is coming in!

[Curly Woods]

I have treated the room already.  I was trying to do some structural things in the room to break up nodes. 

[timind]

Make sure it aint Chinese drywall!

[TRADERXFAN]

  I was thinking of framing out the corners like a triangle(3' from either wall) to remove resonant corners.  Would this be a worthwhile option?

It won't help bass, but it might help the sound by removing the focussing concavity of the corner.  Probably could do it easier with something else and could build in something more useful there than just walling it up.

-Tony

[JLM]

Curly,


First, get the proportions of the room dimensions right.  See Cardas website:

http://www.cardas.com/content.php?area=insights&content_id=26&pagestring=Room+Setup

Bigger is better, but getting the length/width/height ratios correct is even better.  Most spaces are limited by the available ceiling height.  You could even go for the "Golden Trapagon".


Second, make sure the heating/cooling system is quiet.  The easiest step is the use lined/insulated flexible ductwork to isolate the fan noise and eliminate ductwork noises.  Note that wind/traffic noise cannot be ignored, so some sort of insulation, elimination of windows, and use of insulated exterior doors is called for.  Building a room within a room would be ideal.


Electrically try to pull separate 12 gauge/20 amp audio circuits (top of the panel is ideal).  Use a separate grounding rod for the audio circuits.  Hopefully the rest of your home electrical system is in good shape (I have dedicated underground service, whole house surge protector, all 12 gauge/20 amp circuits, and all new appliances).


With great "bones" you'll be in the ideal position to start treating the room with absorption/diffusion.

[bpape]

Instead of using Green Glue why not use ordinary adhesive silicon caulk? Who knows Green Glue might just be ordinary adhesive caulk colored green but with a price surcharge. Is there a secret ingredient or what? Seems to me the point of the adhesive is to provide a flexible elastic layer so just about any sticky rubbery layer would do the job. I've found that many products are just relabeled and marketed for a premium. A case in point are the neoprene/cork footers marketed by Mapleshade and found on Audiogon by other sellers. The same footers are sold by soundproofing.com and others at way (multiples!) lower prices.

-Roy

Sure you can do that - but it's not going to perform anywhere near like Green Glue. 

Bryan

Bryan,

Is it based on your experience or do you know of anyone that has directly compared Green glue to other glues?  Or some measurements of the viscosity or other significant attributes of Green glue in order to base a comparison?  Why are you sure its so much better?

Thanks for the insights...

-Tony

It's based on personal experience and LOTS of serious and well controlled lab testing.  I won't recommend anything else.  Look at the lab results on their web site compared to a lot of other ideas.  Show me ANY other product that has anywhere near that kind of exhaustive and expensive testing that comes anywhere close to this performance.  There aren't any.  Others are just copycats that really don't perform the same. 

There are several threads on other forums where it gets pretty in-depth about different copy-cats.   Nobody has been able to show even close to the same performance under real controlled lab apples to apples comparisons.

Bryan

[bpape]

OK I have a question about a redo of my listening room.  20 feet wide 30 feet long.  Isolation is not an issue as my room is about the garage.  What benefit would double sheet rock provide me in this situation?  Green Glue? The channel system mentioned earlier? 
  I was thinking of framing out the corners like a triangle(3' from either wall) to remove resonant corners.  Would this be a worthwhile option?

No.  Fill them with triangles of 703 floor to ceiling 24 inches at the face to the room.  8 pieces per sheet.  If you frame them and drywall them they you haven't trapped any bass and you're back to square one.  If you don't need to keep sound from bugging others outside the room then you don't need to redo your room unless of course you are on a busy street and the noise is coming in!

Couldn't agree more.  Just chopping off corners is about the worst thing you can do. You're removing an excellent place to treat at the ends of all dimensions while not really doing anything to deal with the decay time and modal issues in the room.  The only thing you're KIND OF eliminating is a little of the horn effect at upper mid and high frequencies at the expense of excellent places to impact low end decay times.

Bryan

[bpape]

With great "bones" you'll be in the ideal position to start treating the room with absorption/diffusion.

Exactly.  Get the core right and you're in a great position to have a great room.  While you may not think you care about isolation, it's MORE about sound getting IN rather than sound getting OUT from a pure performance standpoint.

Bryan

[planet10]

Get Floyd Toole's book. Turns out room dimensions are not all that critical and that a double layer of drywall will probably exacerbate problems with bass.

dave

[rajacat]

I built a studio apartment in the basement of my house. Like the OP, sound transference was a major concern especialy through the ceiling. I started by installing R35 fiberglass insulation between the 2x8 joists. In retrospect I think that this was a mistake and should have installed mineral wool insulation instead because of its greater mass.
     Next I installed cellulose sound board across the joists which I think was good because it's of a different density than sheet rock therefore, I suppose, better at attenuating certain sound frequencies. It also helped to isolate the joists so they wouldn't transfer sound and vibes directly
     Then I screwed resilient channel through the sound board into the joists and hung 5/8" drywall.
Next I screwed up and cut holes through my meticulously installed ceiling for recessed can lights. Since there's only 7'-6" of headroom, I reasoned that flush mounted lights would be a plus. In retrospect, I should have mounted the lights on the walls. It would not be as nice but I wouldn't have destroyed the perfect seal.

Despite my mistakes the sound transference between floors has been markedly attenuated. I did stuff some mass loaded vinyl into the ceiling cans in hope that that would partially correct my error.

Hanging 5/8" drywall to resilient channel is tough work. Another solution that I'd consider is special sound deadening sheet rock. It's more expensive but much less of a PITA.http://quietsolution.com/html/quietrock.html?_kk=sound%20gypsum&_kt=f3b4c8ce-a84d-4eab-b416-46ce4b6160fc&gclid=CP_vrcj4450CFSFRagodRB1rLQ

Another possible solution would be to sandwich 1/16" mass loaded vinyl between two sheets of drywall.

Also you could hang the sheetrock first and then blow in loose cellulose insulation which does a good job of filling any voids. Also I believe it has more mass than fiberglass. Insulate any partition walls or fill with sheetrock  scraps after elec. wiring is finished.

 Here's a good source for materials and advice.
http://www.soundproofing.org/

-Roy 

[bpape]

Get Floyd Toole's book. Turns out room dimensions are not all that critical and that a double layer of drywall will probably exacerbate problems with bass.

dave

It's a double edged sword.

Lower noise floor - good
Lower the resonant frequency of the walls - good
Longer decay times above the resonant frequency prior to treatment - not so good.

Bryan

[bpape]

Read that site with a grain of salt.  There are a few things on there that are questionable at best.

Just some general info for comparison

DD+ GG compared to engineered damped panels
http://www.greengluecompany.com/greenGlue-vs-FactoryDampedPanels.php

DD+GG compared to DD+ MLV between
http://www.greengluecompany.com/greenGlue-vs-MLV.php

GG vs Liquid Nails between layers
http://www.greengluecompany.com/greenGlue-vs-ConstructionAdhesive.php

General technical library for isolation, decoupling, damping, construction, etc.
http://www.greengluecompany.com/technicallibrary.php

Bryan

[TRADERXFAN]

nevermind
-Tony

[ctviggen]

Get Floyd Toole's book. Turns out room dimensions are not all that critical and that a double layer of drywall will probably exacerbate problems with bass.

dave

It's a double edged sword.

Lower noise floor - good
Lower the resonant frequency of the walls - good
Longer decay times above the resonant frequency prior to treatment - not so good.

Bryan

You don't use these techniques because you're worried about exacerbating problems with bass; you use them to reduce the amount of noise coming in and noise/bass going out.  (Or at least that's why I'm doing this.)  For instance, my wife has complained in the past about hearing my music during some infrequent times when I stay up past her.  My daughter is two and is going through all kinds of fears and tends to wake up when the noise isn't periodic, as it isn't in a movie, for instance.  These are my reasons for trying to perform these techniques. 

[rajacat]

Bryan,

Yes, Green Glue does have a lot of technical data to support their product. However, I didn't notice any tests that compare GG to butyl rubber caulk. There's a  GG/construction adhesive test but construction adhesive, after it drys, turns into a relatively hard mass compared to butyl caulk and I presume GG. In fact there's no test that compares GG against any other flexible adhesive caulk.

 GG when compared to engineered panels is slightly better but requires the installation of double layers of 1/2" drywall so the comparison is flawed. . I wonder what the test would conclude if you used 1" engineered panels. Also the extra labor required to install double wallboard is an important cost factor.

 I suppose that the cost of GG, when looking  the whole project, is a small price to pay even if it's just green colored premium adhesive caulk. At $7/tube it's really not much more expensive than the 4 or 5 dollars for a quality alternative.

Just a skeptic here. Well...enough splitting hairs for the day.

-Roy




 

[MaxCast]

I suppose that the cost of GG, when looking  the whole project, is a small price to pay even if it's just green colored premium adhesive caulk. At $7/tube it's really not much more expensive than the 4 or 5 dollars for a quality alternative.

That's the way I looked at it.  Any one thing is not going to yield the desired result but all of them together will give me the best I can do.  Yes, a quality caulk is $5 and you will use a case of it, or more.

[srlaudio]

I also would like to recommend that the sheetrock layers have their seams offset from each other, and each layer be mud and taped to the max.  The devil is in the details!

[ctviggen]

Supposedly, you only need to mud and tape the outer layer.  The inner layer, you can just fill any seams with acoustic caulking.

[Big Red Machine]

Supposedly, you only need to mud and tape the outer layer.  The inner layer, you can just fill any seams with acoustic caulking.

Yeah, no need to mud the inner layers, but I did caulk mine as well as all intersections at wall and ceiling on both layers.

I have one room done this way and an earlier room not treated well at all.  Guess which one is more desirable to be in for all?